1. Technical Field
The present invention relates, in general, to an improved data-processing system and, in particular, to a method and system for eliminating peripheral device conflicts in a multibus data-processing system. Still more particularly, the present invention relates to a method and system for selectively disabling expansion slots associated with one bus in a multibus data-processing system.
2. Description of the Related Art
Modern data-processing systems utilize one or more sets of hardware lines for data transfer among the components of a computer system. The set of hardware lines is referred to as a xe2x80x9cbusxe2x80x9d and is essentially a shared highway that connects different parts of the system, including the microprocessor, disk-drive controller, memory and input/output ports and enables those devices to transfer information. A bus typically consists of specialized groups of lines that carry different types of information. One group of lines may carry data, while another group carries memory addresses where data items may be found. Still another group of lines within the bus may carry control signals. Buses are typically characterized by the number of bits that can be transferred at a single time. Most modern data-processing systems also contain one or more expansion slots into which additional peripheral devices may be plugged to connect those devices to the bus.
Many different types of bus configurations are known in the construction of data-processing systems. For example, the original personal computer, manufactured by International Business Machines Corporation, utilized a bus which supported eight bits at one time. Subsequent improvements to that bus created the so-called xe2x80x9cATxe2x80x9d bus which supports 16 bits of data simultaneously.
More recently, the Industry Standard Architecture (ISA) bus design specification was promulgated which permits peripheral components to be added as cards plugged into standard expansion slots. Peripheral devices or expansion cards plugged into such slots must be configured to operate with the personal computer system. That is, memory locations, specific interrupt requests (IRQ) and various other specifications must be appropriately selected in order for a peripheral device plugged into an Industry Standard Architecture (ISA) bus in order to function properly.
Modern personal computers now often utilize the so-called Peripheral Component Interconnect (PCI) local bus. This specification was introduced by Intel Corporation and defines a local bus system that per to ten PCI-compliant expansion cards to be installed within a computer. A PCI local bus system requires the presence of a PCI controller card, which must be installed in one of the PCI-compliant slots. A PCI controller can exchange data with the system""s central processor at either 32 bits or 64 bits simultaneously, dependent upon the particular implementation, and permits intelligent, PCI-compliant adapters to perform tasks concurrently with the central processor utilizing a technique called bus mastering. Additionally, devices which conform to the xe2x80x9cPlug and Playxe2x80x9d specification permit the computer to automatically configure itself to work properly with peripheral devices plugged into expansion slots which are attached to a PCI local bus.
Many current personal computers include both an ISA bus and a PCI bus. Industry experience has shown that customer support requests are often caused by resource conflicts or loss of functionality which occurs when an end-user improperly installs a peripheral device within an ISA slot, such as a modem, an audio card or multimedia devices. Such conflicts do not occur with a PCI bus as the automatic configuration resolves such conflicts at initiation.
Typically, systems may be shipped by the manufacturer including both ISA and PCI expansion slots because certain functions are only available for ISA expansion slots; however, there exists a large base of customers who do not use ISA expansion slots, and consequently, the ability to prevent an end-user from inserting peripheral devices within ISA expansion slots, thus eliminating possible resource conflicts, would be highly desirable.
Thus, those having skill in the art should appreciate that a method and system for selectively disabling expansion slots associated with an ISA bus could eliminate many customer support calls which are created as a result of resource conflicts.
It is therefore one object of the present invention to provide an improved data-processing system.
It is another object of the present invention to provide an improved method and system for eliminating peripheral device conflicts in a multibus data-processing system.
It is yet another object of the present invention to provide an improved method and system for selectively disabling expansion slots associated with one bus in a multibus data-processing system.
The foregoing objects are achieved as is now described. The method and system of the present invention may be utilized to eliminate peripheral device conflicts in a multibus data-processing system which includes a Peripheral Component Interconnect (PCI) bus having multiple slots for interconnecting peripheral devices in an automatically derived configuration and an Industry Standard Architecture (ISA) bus having multiple slots for interconnecting peripheral devices in a user-selected configuration. Each slot included within the ISA bus includes a reset line for temporarily disabling an associated slot in response to an application of electrical power to the data-processing system, in order to prevent power transition problems. In response to an existing or potential peripheral device conflict brought about by a user-selected configuration, a control signal is selectively applied to the reset line for one or more slots included within the ISA bus, thus temporarily disabling those slots during normal operation of the data-processing system.
The above, as well as additional objectives, features and advantages of the present invention, will become apparent in the following detailed written description.